Differential visualization of countoured surfaces

Abstract

A method and a system for visualizing differences of three-dimensional contour surfaces, in particular of three-dimensional contour surfaces produced by virtually machining a workpiece, are described. The method determines a first and second surface and spatial and/or volume differences between the contours of these surfaces. One of the surfaces together with the determined spatial and/or volume differences between the contours of the surfaces can be graphically rendered, wherein the differences are rendered as an additional attribute of the one surface, for example, in a different color.

1. A method for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising the steps of:
 determining a first and second surface;  
 determining spatial differences between contours of the determined first and second surfaces; and  
 graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface,  
 wherein graphically rendering the one surface includes protecting the determined spatial differences onto the one surface as interpolated values.  
 
     
     
       2. The method of  claim 1 , wherein the projected spatial differences are projected in a color, and wherein the projected color is different from a color of the one surface. 
     
     
       3. A method for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising the steps of:
 determining a first and second surface;  
 determining spatial differences between contours of the determined first and second surfaces;  
 graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface; and  
 modeling the spatial differences between the contours as volume values that are rendered as interpolated colors, and applying the volume values to the one surface before the one surface is graphically rendered.  
 
     
     
       4. A method for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising the steps of:
 determining a first and second surface;  
 determining spatial differences between contours of the determined first and second surfaces; and  
 graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface,  
 wherein the contours of the first and second surfaces are defined analytically and the spatial differences are determined continuously based on values derived from the analytically defined contours of the first and second surfaces.  
 
     
     
       5. A method for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising the steps of:
 determining a first and second surface;  
 determining spatial differences between contours of the determined first and second surfaces;  
 graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface;  
 determining from workpiece data a plurality of discrete support points in three-dimensional space, and  
 determining for each surface a grid surface based on the discrete support points,  
 wherein the spatial difference between the grid surfaces of the first and second surface is obtained by forming a difference between corresponding support points located on the first and second grid surfaces.  
 
     
     
       6. The method of  claim 5 , and further comprising the steps of defining a family of straight lines extending parallel to a first coordinate axis in three-dimensional space; modeling the workpiece with a blank workpiece using the family of straight lines; intersecting the family of straight lines with a virtual machining tool according to a predetermined machining path to form scanned volumes; and forming from the resulting points of intersection of all scanned volumes a grid surface corresponding to a workpiece contour. 
     
     
       7. The method of  claim 6 , wherein when simulating machining in three coordinate axes, only those points of intersection with a straight line are considered for forming the grid surface that have the smallest coordinate value in the direction of the straight line. 
     
     
       8. The method of  claim 6 , wherein for a straight line without a point of intersection with the virtual machining tool, an initialization value is used for forming the grid surface. 
     
     
       9. The method of  claim 6 , and further comprising the step of arranging the straight lines of the family of straight lines with a discrete equidistant spacing along those coordinate axes that are different from the first coordinate axis. 
     
     
       10. A device for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising:
 means for determining a first and second surface;  
 means for determining spatial differences between contours of the determined first and second surfaces; and  
 means for graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface,  
 wherein graphically rendering the one surface includes protecting the determined spatial differences onto the one surface as interpolated values.  
 
     
     
       11. Computer program product adapted to execute on a digital computer, for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, the computer program product comprising:
 computer program instructions for determining a first and a second surface;  
 computer program instructions for determining spatial difference values between contours of the determined first and second surfaces; and  
 computer program instructions for graphically rendering one of the surfaces together with the determined spatial difference values between the contours of the determined first and second surfaces, said determined spatial difference values forming an additional attribute of the one surface,  
 wherein graphically rendering the one surface includes protecting the determined spatial differences onto the one surface as interpolated values.  
 
     
     
       12. The method of  claim 10 , wherein the projected spatial differences are projected in a color, and wherein the projected color is different from a color of the one surface. 
     
     
       13. A device for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising:
 means for determining a first and second surface;  
 means for determining spatial differences between contours of the determined first and second surfaces;  
 means for graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface;  
 means for modeling the spatial differences between the contours as volume values that are rendered as interpolated colors, and  
 means for applying the volume values to the one surface before the one surface is graphically rendered.  
 
     
     
       14. A device for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising:
 means for determining a first and second surface;  
 means for determining spatial differences between contours of the determined first and second surfaces; and  
 means for graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface,  
 wherein the contours of the first and second surfaces are defined analytically and the spatial differences are determined continuously based on values derived from the analytically defined contours of the first and second surfaces.  
 
     
     
       15. A device for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, comprising:
 means for determining a first and second surface;  
 means for determining spatial differences between contours of the determined first and second surfaces; and  
 means for graphically rendering one of the surfaces together with the determined spatial differences between the contours of the determined first and second surfaces, said determined spatial differences forming an additional attribute of the one surface,  
 wherein a plurality of discrete support points is determined from workpiece data in three-dimensional space,  
 wherein for each surface a grid surface is determined based on the discrete support points, and  
 wherein the spatial difference between the grid surfaces of the first and second surface is obtained by forming a difference between corresponding support points located on the first and second grid surfaces.  
 
     
     
       16. The device of  claim 15 , wherein a family of straight lines extending parallel to a first coordinate axis is defined in three-dimensional space, wherein the workpiece is modeled with a blank workpiece using the family of straight lines, with the family of straight lines intersecting with a virtual machining tool according to a predetermined machining path to form scanned volumes, and wherein from the resulting points of intersection of all scanned volumes a grid surface is formed that corresponds to a workpiece contour. 
     
     
       17. The device of  claim 16 , wherein when simulating machining in three coordinate axes, only those points of intersection with a straight line are considered for forming the grid surface that have the smallest coordinate value in the direction of the straight line. 
     
     
       18. The device of  claim 16 , wherein for a straight line without a point of intersection with the virtual machining tool, an initialization value is used for forming the grid surface. 
     
     
       19. The device of  claim 16 , wherein the straight lines of the family of straight lines are arranged with a discrete equidistant spacing along those coordinate axes that are different from the first coordinate axis. 
     
     
       20. The computer program product of  claim 11 , wherein the projected spatial differences are projected in a color, and wherein the projected color is different from a color of the one surface. 
     
     
       21. Computer program product adapted to execute on a digital computer, for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, the computer program product comprising:
 computer program instructions for determining a first and a second surface;  
 computer program instructions for determining spatial difference values between contours of the determined first and second surfaces; and  
 computer program instructions for graphically rendering one of the surfaces together with the determined spatial difference values between the contours of the determined first and second surfaces, said determined spatial difference values forming an additional attribute of the one surface,  
 computer program instructions for modeling the spatial differences between the contours as volume values that are rendered as interpolated colors, and computer program instructions for applying the volume values to the one surface before the one surface is graphically rendered.  
 
     
     
       22. Computer program product adapted to execute on a digital computer, for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, the computer program product comprising:
 computer program instructions for determining a first and a second surface;  
 computer program instructions for determining spatial difference values between contours of the determined first and second surfaces; and  
 computer program instructions for graphically rendering one of the surfaces together with the determined spatial difference values between the contours of the determined first and second surfaces, said determined spatial difference values forming an additional attribute of the one surface,  
 wherein the contours of the first and second surfaces are defined analytically and the spatial differences are determined continuously based on values derived from the analytically defined contours of the first and second surfaces.  
 
     
     
       23. Computer program product adapted to execute on a digital computer, for differential visualization of two three-dimensional contoured surfaces, in particular of workpieces, the computer program product comprising:
 computer program instructions for determining a first and a second surface;  
 computer program instructions for determining spatial difference values between contours of the determined first and second surfaces; and  
 computer program instructions for graphically rendering one of the surfaces together with the determined spatial difference values between the contours of the determined first and second surfaces, said determined spatial difference values forming an additional attribute of the one surface,  
 computer program instructions for determining from workpiece data a plurality of discrete support points in three-dimensional space, and  
 computer program instructions for determining for each surface a grid surface based on the discrete support points, wherein the spatial difference between the grid surfaces of the first and second surface is obtained by forming a difference between corresponding support points located on the first and second grid surfaces.  
 
     
     
       24. The computer program product of  claim 23 , and further comprising computer program instructions for
 defining a family of straight lines extending parallel to a first coordinate axis in three-dimensional space;  
 modeling the workpiece with a blank workpiece using the family of straight lines; intersecting the family of straight lines with a virtual machining tool according to a predetermined machining path to form scanned volumes; and forming from the resulting points of intersection of all scanned volumes a grid surface corresponding to a workpiece contour.  
 
     
     
       25. The computer program product of  claim 24 , wherein when simulating machining in three coordinate axes, only those points of intersection with a straight line are considered for forming the grid surface that have the smallest coordinate value in the direction of the straight line. 
     
     
       26. The computer program product of  claim 24 , wherein for a straight line without a point of intersection with the virtual machining tool, an initialization value is used for forming the grid surface. 
     
     
       27. The computer program product of  claim 24 , and further comprising computer program instructions for arranging the straight lines of the family of straight lines with a discrete equidistant spacing along those coordinate axes that are different from the first coordinate axis.